The FOXGM2 carrier board allows you to extend the functionality of the FOX Board G20. It has a port where you can install a Telit GM862-QUAD, GM862-GPS or GSM Booster modem, mounting pads for you to solder the FOX Board G20, and a port to attach a DAISY-23 LCD & buttons panel.

The picture below shows how a complete system will look. You see this FOXGM2 carrier board with a FOX Board G20 mounted on top, and a Telit modem on the bottom with a SIM card and antenna cable. The G20, modem, SIM card and antenna cable are not included. This order page only is for the carrier board (shown in the images on the right).

Using the FOXGM2 Carrier Board

Note that the following instructions assume you have purchased a FOX Board G20 and a Telit modem and have installed them on this board.

Modem power on

At startup, the modem is off. You can turn it on by pressing the pushbutton on the FOXGM2 carrier board, or via the FOX Board using these two lines:

Telit ON signal on FOX pin J6.37. This pin is used to turn on the modem. The normal state is low. A 1-second pulse at 1 will turn on or turn off the modem. The state of this signal is inverted compared to the Telit datasheet.

Telit RESET signal on FOX pin J6.38. This pin is used to reset the modem logic. The normal state is low. A 1-second pulse at 1 will reset the modem. The state of this signal is inverted compared to the Telit datasheet.

The telit_on.py source in Python shows how to turn on the modem. To use it, you'll also need to install the fox.py module. You can find both of these in the FOX G20 GitHub repository.

You will see a response Telit ON/OFF and the red LED LD2 will begin blinking. This LED is managed directly by the Telit CPU and indicates its internal state.

The same command can be used to turn off the modem. The button on the FOXGM2 carrier board also can turn on/off the modem.

Sending AT commands to the modem

When the modem is on, you can use AT commands to communicate with it. The serial port used is /dev/ttyS1.

The easiest way to send commands is using the serial terminal emulator, minicom. Run minicom by typing:

debarm:/# minicom -s

The -s option gives you access to the configuration menu. Select Serial port setup from the menu, then type A to edit the Serial Device line. Enter /dev/ttyS1

Save the configuration using Save setup as dfl, then select Exit.

Now type at and you should see an OK response from the modem. Refer to the Telit Modules Software User Guide to discover the complete set of AT commands available.

Read GPS data from the NMEA ports

On the Telit GM862-GPS, a serial port is reserved for GPS data in NMEA format. This port is /dev/ttyS2. To read it, open a new terminal session with the FOX board. Run minicom -s and set Serial Device to /dev/ttyS2, set Hardware Flow Control to No and set Bps/Par/Bits to 4800 8N1

Now select Exit and you should see the NMEA data flow on your terminal.